| 摘要 |
PURPOSE: A Pt or Ag based bimetallic catalyst and its preparation method are provided, which catalyst is used for preparing an electrochemical cells having oxygen-reducing cathode, to reduce or remove the aggregation of Pt or Ag particles. CONSTITUTION: The stabilized bimetallic catalyst comprises a conducting support; and a metal-plated coating comprising the first metal M1 selected from Pt and Ag and the second metal M2 which is different from M1 and selected from the group consisting of Pt, Ag, Au, Rt, Ir, R and Os. Preferably the conducting support is a carbon-based material with the specific surface area above 50 square meter per gram, and one of the M1 and M2 is Pt and the other is Ag. The bimetallic catalyst is prepared by impregnating the conducting support with a metal salt solution of the M1 and a metal salt solution of the M2; evaporating the suspension slowly under stirring and under inert gas bubbling to dry it; drying the obtained powder at atmospheric pressure at 60-80°C, then under reduced pressure at 90-110°C; and heating the obtained powder under hydrogen at 300-600°C whose heating rate was 0.2-1.5°C/min for 20 hours, preferably 2-16 hours. |
